first′ class′
n. 1. the best, finest, or highest class, grade, or rank.
2. the most expensive and most luxurious class of accommodation on trains, ships, airplanes, etc.
3. (in the U.S. Postal Service) the class of mail consisting of letters, postal cards, or the like, together with all mailable matter sealed against inspection.
[1740–50]
first′-class′
adj. 1. of the highest or best class or quality.
2. best-equipped and most expensive.
3. given or entitled to preferred treatment, handling, etc.
adv. 4. by first-class conveyance.
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